View source for Geertruida de Haas-Lorentz

{{Short description|Dutch physicist (1885–1973)}}
{{use dmy dates|date=July 2024}}
{{Family name hatnote|Lorentz|De Haas-Lorentz||lang=Dutch|nd=De Haas}}
{{Dutch name capitalization|De Haas|De Haas-Lorentz}}
{{Infobox scientist
| image             = Mej. G.L. Lorentz, before 1909.jpg
| caption           = Miss G.L. Lorentz, before 1909, employed by the Polytechnische School Delft, Netherlands.
| birth_name        = Geertruida Luberta Lorentz
| birth_date        = {{birth date|df=y|1885|10|20}}
| birth_place       = [[Leiden]], [[South Holland]], Netherlands
| death_date        = {{death year and age|1973|1885}}
| death_place       = Leiden, South Holland, Netherlands
| alma_mater        = [[University of Leiden]]
| known_for         = First to perform fluctuational analysis of electrons as [[Brownian motion|Brownian]] particles
| spouse            = {{marriage|[[Wander Johannes de Haas]]|1910|1960|end=d}}
| children          = 4
| father            = [[Hendrik Lorentz]]
| mother            = Aletta Catharina Kaiser
| fields            = [[Physics]]
| work_institutions = [[Technical University of Delft]]
| thesis_title      = Over de theorie van de Brown'schen beweging en daarmede verwante verschijnselen
| thesis_url        = https://ilorentz.org/history/proefschriften/sources/deHaasLorentz_1912.pdf
| thesis_year       = 1912
| doctoral_advisor  = Hendrik Lorentz
}}
[[File:Proprieted'AlbertKahn-Boulogne-FranceMadameGeertruidadeHaas-Lorentz A51581.jpg|thumb|De Haas-Lorentz in 1927.]]
'''Geertruida Luberta "Berta" de Haas-Lorentz''' (20 November 1885 – 1973) was a Dutch [[physicist]] and a professor at the [[Delft University of Technology|Technical University of Delft]]. She was the first to theoretically study [[thermal fluctuations]] in [[electric circuit]]s, treating [[Electron|electrons]] as [[Brownian motion|Brownian]] particles. Consequently she is considered one of the pioneers of [[Electronic noise|electrical noise]] theory. She was the daughter and doctoral student of [[Hendrik Lorentz]]. She went by the name Berta, or Ber.{{sfn|Kox|Schatz|2021|p=38}}

== Life ==
Berta Lorentz was born in Leiden, Netherlands, the eldest daughter of the physicist and 1902 [[Nobel Prize in Physics]] winner [[Hendrik Lorentz]] and Aletta Catharina Kaiser. Berta was the eldest of four children. Her siblings were Johanna Wilhelmina (born 1889), Gerrit (born 1893, died 1894), and Rudolf (born 1895).{{sfn|Kox|Schatz|2021|p=39}} At that time of her birth, her father was Professor of Theoretical Physics at the [[University of Leiden]].<ref name=":0">{{Cite book |last=Parkadze |first=V. |title=Women Physicists |year=1988 |location=Tbilisi |pages=71–75}}</ref> Her mother, Aletta Kaiser, took care of the children and household, did charity work, and was heavily involved with the local women's suffrage movement.{{sfn|Kox|Schatz|2021|pp=42-44}}

On 22 December 1910, Berta Lorentz married [[Wander Johannes de Haas]], who would become professor of experimental physics in Leiden, and they went on to have two sons and two daughters. Some of their children changed their last name to "Lorentz de Haas."{{sfn|Kox|Schatz|2021|p=257}}<ref>{{Cite web |title=To the Memory of A.M. Lorentz de Haas |url=https://www.ilae.org/files/ilaeFarewell/AlbertMLorentzdeHaasobituary1911%2D1967.pdf }}</ref>

She studied physics at the [[University of Leiden]] with her father as dissertation advisor<ref>{{Cite web |last=De Haas-Lorentz |first=Geertruida |title=Math Genealogy Project |url=https://www.genealogy.math.ndsu.nodak.edu/id.php?id=108141 |access-date=2020-10-24}}</ref> and earned her doctor's degree in 1912 on a thesis entitled "On the theory of [[Brownian motion]] and related phenomena" ({{Langx|nl|Over de theorie van de Brown'schen beweging en daarmede verwante verschijnselen}}).<ref>{{Cite web |last=De Haas-Lorentz |first=Geertruida |year=1912 |title=Over de theorie van de Brown'sche beweging en daarmede verwante verschijnselen |trans-title=On the theory of Brownian motion and related phenomena |url=http://ilorentz.org/history/proefschriften/sources/deHaasLorentz_1912.pdf}}</ref> 

After defending her doctoral dissertation in Leiden, De Haas-Lorentz taught physics at the [[Delft University of Technology|Technical University of Delft]] and translated some of her father's works into German.<ref name=":0" /> She also wrote a biography of her father.<ref>{{Cite book |last=De Haas-Lorentz |first=Geertruida Luberta |url=https://books.google.com/books?id=OJHQAAAAMAAJ&q=HA+Lorentz:+Impressions+of+His+Life+and+Work |title=H.A. Lorentz: Impressions of His Life and Work |date=1957 |publisher=North-Holland Publishing Company |language=en}}</ref>

Berta de Haas-Lorentz died in 1973 in Leiden.

== Research ==
De Haas-Lorentz was one the first to apply [[Albert Einstein]]'s theory of [[Brownian motion]] to other domains.<ref name=":2">{{Cite book |last=Van Der Ziel |first=A. |chapter-url=https://www.sciencedirect.com/science/article/pii/S0065253908610665 |title=Advances in Electronics and Electron Physics |date=1980-01-01 |publisher=Academic Press |isbn=978-0-12-014650-5 |editor-last=Marton |editor-first=L. |volume=50 |pages=351–409 |chapter=History of Noise Research |doi=10.1016/S0065-2539(08)61066-5 |access-date=2024-03-16 |editor-last2=Marton |editor-first2=C.}}</ref> During her thesis work, she was the first to carry out a theoretical analysis of thermal fluctuation of electrons in electrical circuits, predating the experimental discovery of the [[Johnson–Nyquist noise]].<ref>{{Cite journal |last=Dörfel |first=G. |date=2012-08-15 |title=The early history of thermal noise: The long way to paradigm change |url=https://onlinelibrary.wiley.com/doi/10.1002/andp.201200736 |journal=Annalen der Physik |language=en |volume=524 |issue=8 |pages=117–121 |doi=10.1002/andp.201200736 |bibcode=2012AnP...524..117D |issn=0003-3804}}</ref> She considered that a circuit with resistance ''R'' and inductance ''L'' should store an energy {{Math|''E'' {{=}} ''LI''<sup>2</sup>/2}}, where ''I'' is the current. If there was a fluctuating thermal current, by the [[equipartition theorem]] the energy would be related to the thermal energy [[KT (energy)|''kT'']] where ''k'' is the [[Boltzmann constant]] and ''T'' is the temperature. De Haas-Lorentz obtained,
: <math>\sqrt{\langle I^2\rangle}=\sqrt{ \frac{2 k T}{ L }}</math>,
where the angle brackets denote the thermal average.<ref>{{Cite book |last=Yeang |first=Chen-Pang |url=https://books.google.com/books?id=xUbaEAAAQBAJ&dq=geetruida+lorentz&pg=PA165 |title=Transforming Noise: A History of Its Science and Technology from Disturbing Sounds to Informational Errors, 1900-1955 |date=2024-01-30 |publisher=Oxford University Press |isbn=978-0-19-888776-8 |language=en}}</ref>

She was also the first to propose thermal fluctuations limit the detection of [[electromagnetic radiation]].<ref name=":2" />

In collaboration with her husband, the De Haas couple showed that experiments carried by [[James Clerk Maxwell]] failed to prove the hypothesis of [[André-Marie Ampère]], that magnetism in matter is caused by microscopic [[current loop]]s.<ref>{{Cite journal |last1=Haas |first1=W. J. |last2=Haas-Lorentz |first2=G.L. |date=1917 |title=An experiment of Maxwell and Ampere molecular currents |url=https://dwc.knaw.nl/DL/publications/PU00012351.pdf |journal=KNAW, Proceedings |location=Amsterdam |volume=19 |issue=I |pages=248–255|bibcode=1917KNAB...19..248D }}</ref><ref>{{Cite journal |last1=San Miguel |first1=Alfonso |last2=Pallandre |first2=Bernard |date=13 March 2024 |title=Revisiting the Einstein-de Haas experiment: the Ampère Museum's hidden treasure |url=https://www.europhysicsnews.org/images/stories/news/epn_Einstein-de_Haas.pdf |journal=Europhysics News |pages=12–14}}</ref>
[[File:Geertruida de Haas-Lorentz with father Hendrik Lorentz.jpg|alt=outdoors, Geertruida is holding one child and Hendrik is holding the other|thumb|Geertruida de Haas-Horentz,  center, with father Hendrik Lorentz (kneeling) and two small children (unknown)]]
She also predicted the [[London penetration depth]] for [[superconductivity]] in 1925, before the development of the [[London equations]] in 1935.<ref name=":1">{{Cite book |last1=Fossheim |first1=Kristian |title=Superconductivity: physics and applications |last2=Sudbø |first2=Asle |publisher=John Wiley & Sons |year=2005}}</ref><ref>{{Cite journal |last=De Haas-Lorentz |first=G. L. |date=1925 |title=Iets over het mechanisme van inductieverschijnselen |journal=Physica |language=nl |volume=5 |pages=384–388}}</ref>

== Selected works ==
* {{Cite thesis |last=De Haas-Lorentz |first=Geertruida |title=Over de theorie van de Brown'sche beweging en daarmede verwante verschijnselen |trans-title=On the theory of Brownian motion and related phenomena |degree=Doctoral dissertation |publisher=University of Leiden |url=https://ilorentz.org/history/proefschriften/sources/deHaasLorentz_1912.pdf |year=1912 |ref=none |lang=nl}}
* {{Cite book |last=De Haas-Lorentz |first=Geertruida |title=Die Brownsche Bewegung und einige verwandte erscheinungen |publisher=F. Vieweg |trans-title=Brownian motion and some related phenomena |year=1913 |location=Braunschweig |oclc=5160522 |ref=none |lang=de}}
* {{Cite book |last1=De Haas-Lorentz |first1=Geertruida |title=Theorie der quanta |trans-title=Theory of quanta |last2=Lorentz |first2=H. A. |year=1919 |oclc=81861598 |ref=none}}
* {{Cite book |title=Lessen over theoretische natuurkunde : aan de Rijks-Universiteit te Leiden |trans-title=Lessons on theoretical physics at Leiden State University |year=1919–1926 |volume=1-5 |oclc=805502380}} {{endash}} contributing author
* {{Cite book |last1=Lorentz |first1=H. A. |title=Kinetische Probleme |trans-title=Kinetic Problems|last2=Bruins |first2=Eva Dina |last3=Reudler |first3=Johanna |last4=De Haas-Lorentz |first4=Geertruida Luberta |publisher=Akademische Verlagsgesellschaft |year=1928 |location=Leipzig |oclc=28005510 |ref=none |lang=de}}
* {{Cite book |last=De Haas-Lorentz |first=Geertruida Luberta |title=De beide hoofdwetten der thermodynamica en hare voornaamste toepassingen |trans-title=The two main laws of thermodynamics and their main applications |publisher=M. Nijhoff |year=1946 |location='s-Gravenhage |oclc=361410098 |ref=none |lang=nl}}
* {{Cite book |title=H. A. Lorentz: impression of his life and work |publisher=North-Holland Pub. Co. |year=1957 |editor-last=De Haas-Lorentz |editor-first=Geertruida Luberta |location=Amsterdam |oclc=317334917 |ref=none}}

== Notes ==
{{reflist}}

== References ==
* {{Cite book |last1=Kox |first1=Anne J. |title="A living work of art": the life and science of Hendrik Antoon Lorentz |last2=Schatz |first2=H. F. |date=2021 |publisher=Oxford University Press |isbn=978-0-19-887050-0 |edition=1st |location=Oxford |pages=38 |oclc=on1194958040}}

== External links ==
* [http://www.lorentz.leidenuniv.nl/IL-publications/dissertations/lorentz.html Ph.D. students of H.A. Lorentz: 1881-1921]
* [http://www.lorentz.leidenuniv.nl/IL-publications/dissertations/photographs/deHaasLorentz.jpg Photo of De Haas-Lorentz]
* {{MathGenealogy|108141}}

{{Authority control}}

{{DEFAULTSORT:Haas Lorentz, Geertruida Luberta De}}
[[Category:1885 births]]
[[Category:1973 deaths]]
[[Category:20th-century Dutch physicists]]
[[Category:Dutch women physicists]]
[[Category:Leiden University alumni]]
[[Category:Scientists from Leiden]]
[[Category:20th-century Dutch women scientists]]
[[Category:20th-century women physicists]]